Craniofacial Suture Fusion in Primates

Abstract

Timing of craniofacial suture fusion is important to questions of demographics and primate ontogeny. There has been much work concerning the fusion of calvarial sutures over the last century, but little work focusing on facial sutures. Here we assess the relationships of facial suture fusion among primates. 1436 skulls of Homo, Pan, Gorilla, Pongo, Hylobates, Macaca and Papio were observed at 5 facial suture sites for stage of fusion. Calvarial volume (early) and dental eruption (late) were utilized as indicators of stage of ontogeny. Patterns of fusion were assessed by Gutmann scaling. Homogeneity of slopes and ANOVA were used to determine differences in timing of fusion. All groups demonstrated reproducible patterns of fusion within groups but variation suggesting slightly different sites of onset and termination of suture fusion between species groups. For calvarial growth, groups segregated by regression slopes, Homo having a very steep slope, indicating remodeling throughout ontogeny, less steep slopes for Pongo, Macaca, and Papio, and flat regression slopes Pan, Gorilla, and Hylobatiadae, indicating very early facial suture remodeling. Similar patterns are observed when dental eruption is used for staging. Thus, Homo appears to be unique in its delay and patency of sutures into late ontogeny. Only Gorilla and Hylobatidae are observed to, as a general rule, fuse all facial suture sites by senescence.Grant Funding Source: N//A